It is known in the art relating to diesel engine cylinders to provide a cast bore having a surrounding coolant jacket which may be cast integrally or formed otherwise such as by a fabricated assembly of a cast bore section and an outer sleeve brazed or otherwise secured to the casting to form an annular coolant jacket.
In a commonly used liner for two cycle engines, a flange is provided with eight equally spaced studs which are threaded into the liner flange and extend therefrom for retention of an associated pot type cylinder head in sealing engagement with flange. The studs are seated in thickened portions of the flange formed as ribs which connect inner and outer portions and blend downward into the bore wall.
Between the ribs, the flange is hollow to form upper extensions of the coolant jacket that cool the upper bore and pass coolant into drilled passages that carry the coolant to the cylinder head. Sections of the flange between liner studs are provided alternately with one or two drilled passages forming coolant outlet openings which are aligned with inlet openings formed in the associated cylinder head.
One such prior cylinder liner is shown in U.S. Pat. No. 4,093,842 issued June 6, 1978. That liner is of fabricated construction having an alloy cast iron body and flanges receiving separately formed sleeves closing upper and lower coolant jackets that are connected through coolant passages extending between centrally located air inlet ports. Other prior liners have been made with fully cast bodies forming integral coolant jackets.
As shown in Pat. No. 4,093,842, the prior liner upper flange 26 includes hollow portions extending upwardly from the coolant jacket 38 to cool the upper bore wall 24. Passages 48 through the flange 26 connect the jacket 38 with inlet openings 19 of an associated cylinder head 10 as shown in FIG. 1 of U.S. Pat. No. 4,918,805 issued Apr. 24, 1990.
Between the hollow portions, the flange 26 of liners like that of Pat. No. 4,093,842 has ribs, not shown, extending to the bottom of the flange and below it with the bore wall 24. In these ribs are threaded openings, not shown, to receive eight studs, not shown. In assembly with a head similar to that of Pat. No. 4,918,805, these studs extend through bores 22 in the barrel 12 of the associated cylinder head 10 for securing the barrel against the liner flange.
Typically, a thin metal combustion gasket is used between the head and liner surfaces to seal combustion gases, although other types of gaskets have been used. Annular grommets (resilient seal rings) with or without surrounding insulator rings have been used as seals in individual flange recesses to seal the joints between the liner and cylinder head coolant passages against leakage of coolant.
Such cylinder liners have given many years satisfactory service in commercial use. However, it has been found that the high clamping forces applied to the studs for retaining the associated liner and cylinder head in sealing engagement have tended to cause some distortion of the upper cylinder bore, apparently due to an outward pulling of the bore wall at the rib locations.